The present invention relates to systems and methods for removing greenhouse gases from the atmosphere, and in particular to systems and methods for removing carbon dioxide from a stream of gas, including ambient air.
As a further improvement to the system described in copending U.S. application Ser. No. 13/098,370, filed on Apr. 29, 2011, a suitable system and process is presented that it is now recognized can be utilized for a broader range of use than disclosed in that earlier application, especially when further modified. The disclosure of that copending application is incorporated by reference herein as if repeated in full, as modified by the new disclosure presented herein.
There is much attention currently focused on trying to achieve three somewhat conflicting energy related objectives: 1) provide affordable energy for economic development; 2) achieve energy security; and 3) avoid the destructive climate change caused by global warming. However, there is no feasible way to avoid using fossil fuels during the rest of this century if we are to have the energy needed for economic prosperity and avoid energy shortfalls that could lead to conflict.
It is mostly undisputed by scientists that an increase in the amount of so-called greenhouse gases like carbon dioxide (methane and water vapor are the other major greenhouse gases) will increase the average temperature of the planet.
It is also clear that there is no solution that only reduces the ongoing human contributions to carbon dioxide emissions that can successfully remove the risk of climate change. Removing additional CO2 from the atmosphere is also necessary. With air extraction and the capability to increase or decrease the amount of carbon dioxide in the atmosphere, one can in principle compensate for other greenhouse gases like methane (both naturally occurring and from human activity) that can increase their concentrations and cause climate change.
Until the recent inventions by the present applicant, it was the generally accepted belief among experts in the field that it was not economically feasible to capture carbon dioxide directly from the atmosphere because of the low concentration of that compound, in order to at least slow down the increase of so-called ‘greenhouse’ gases in the atmosphere. It was subsequently shown by the copending, commonly owned, prior applications that it was in fact practical and efficient to carry out such CO2 reductions under specified conditions.
It was shown that under ambient conditions CO2 can be efficiently extracted from the air, at ambient conditions, using a suitable regenerable sorbent system and a low temperature stripping or regeneration process, and that such a process can be expanded to remove CO2.from mixtures of effluent gases mixed with a major amount of ambient air, so as to not only remove the CO2 from flue gas but to remove additional CO2 from the atmosphere so as to achieve a net reduction in CO2 in the atmosphere at lower cost and higher efficiency.